323,984 research outputs found
Improved fallows in Eastern Zambia: history, farmer practice and impacts
No full text"The decline in soil fertility in smallholder systems is a major factor inhibiting equitable development in much of sub-Saharan Africa. Some areas fallow in order to strength soil fertility for later planting, but as populations increase, demand follows and continuous cropping becomes the norm and there is a reduction in yields. This case study summarizes the development of improved tree fallows by researchers and farmers in eastern Zambia to help solve the problem of poor soil fertility. Many farmers are finding that by using improved fallows, they can substitute relatively small amounts of land and labor for cash, which they would need to buy mineral fertilizer. The study has three phases: the historical background (phase 1); an assessment of problems, description of the technology, and how it was developed (phase 2); and how the improved fallows practices were disseminated and spread (phase 3). This paper will describe each phase, the goals, and results." Authors' AbstractSouthern Africa, africa south of sahara, Crop yields,
Factors influencing adoption of agroforestry among smallholder farmers in Zambia
No full textAgroforestry technologies have been extensively researched and introduced to smallholder farmers in Zambia for over two decades. Despite the research and extension effort over this period, not many farmers have adopted these technologies. The purpose of this paper is to determine why agroforestry technologies are not being taken up by examining factors that influence the adoption of agroforestry practices. Based on data obtained from 388 farming households, statistical analysis show an association between adoption of both improved fallows and biomass transfer technologies with knowledge of the technology, availability of seed, and having the appropriate skills. In addition some household characteristics are found to be linked to the incidence of adoption. However, the strength of association between these variables is low, giving an indication that there might be other factors at play limiting agroforestry adoption. It is anticipated that these findings will point to other areas beyond the household and community level that need further exploration in order to understand factors limiting agroforestry adoption.Agroforestry adoption, smallholder farmers, limitations to adoption, chi-square tests of independence analysis, Zambia, Agricultural and Food Policy, Community/Rural/Urban Development, Crop Production/Industries, Environmental Economics and Policy, Land Economics/Use,
Species richness and habitat diversification of bryophytes in submontane rain forest and fallows of Bolivia
No full textAn analysis of corticolous bryophyte diversity on whole trees in primary rain forest and 4-15-y-old fallows at 500-650 m in the Alto Beni, Bolivia, showed a significantly decreased diversity of bryophyte families and moss species in the fallows. However, liverwort diversity was scarcely lower in the fallows, except in the very young (4 y old) ones. Fallows had a significantly higher percentage of smooth mat species (72%), which may reflect the warmer, drier microclimate in the fallows. About half of the bryophyte species of the rain forest had re-established in the 10-15-y-old fallows. The majority of these are ecological generalists and sun epiphytes; a small minority are shade epiphytes. Re-establishment of ecological specialists is slower than that of generalists. Species richness in the primary forest is highest in the canopy; in the fallows it is highest in the understorey due to striking shifts of species and specialized growth types (rough mats, fans, tails) towards lower heights on the trees in the fallows. These shifts correspond well with measured changes in air temperature and air humidity in the fallows as compared with the forest
Fallows, W J, WX15516
No full textThis record was harvested from a previous catalogue system and will be withdrawn in 2025. Information in this record may be superseded or incomplete. Visit this record in UMA's new catalogue at: https://archives.library.unimelb.edu.au/nodes/view/384503Surname: FALLOWS. Given Name(s) or Initials: W J. Military Service Number or Last Known Location: WX15516. Missing, Wounded and Prisoner of War Enquiry Card Index Number: 35647.230245
Item: [2016.0049.16796] "Fallows, W J, WX15516
Fallows, William T, WX17228
No full textThis record was harvested from a previous catalogue system and will be withdrawn in 2025. Information in this record may be superseded or incomplete. Visit this record in UMA's new catalogue at: https://archives.library.unimelb.edu.au/nodes/view/384504Surname: FALLOWS. Given Name(s) or Initials: WILLIAM T. Military Service Number or Last Known Location: WX17228. Missing, Wounded and Prisoner of War Enquiry Card Index Number: 42758.230246
Item: [2016.0049.16797] "Fallows, William T, WX17228
An evaluation of exciterless topologies for medium power wound-field synchronous generators
No full textThe wound field synchronous machine has widespread use both as a motor and a generator, due to its low cost, wide power range and its consolidated history built over decades of operation. A critical aspect of these machines is the method of excitation to the field winding. Typically, the choice is between a static excitation system using slip-rings and a rotating excitation system using a brushless exciter. An alternative is that of removing the classical exciter completely and thus feed the field winding through more advanced 'exciterless' solution. The potential to reduce component count and improve power density has resulted in increasing interest in exciterless solutions, over the last couple of decades. This paper thus gives an overview of these methods, assessing and comparing their advantages and disadvantages. A particular focus is on medium power applications, which traditionally have dominated the market of synchronous generators and associated generating sets, and where significant improvements in terms of cost minimisation, power quality, and ease of design are always required
Developments in the use of EISCAT for interplanetary scintillation
No full textThe antennas of EISCAT have been used for interplanetary scintillation (IPS) studies of the solar wind for many years. The main science found from these studies is obtained through the cross-correlation of signals from antennas having the longest baseline, providing more accurate information on the different solar wind streams which may be present in the line of sight. The development of dual-frequency IPS observations between the 1.4 GHz receivers at the remote sites and Tromso, has allowed the use of the EISCAT Svalbard Radar for IPS, increasing the available baselines to the extent that three solar wind streams can sometimes be identified in the cross-correlation functions. A weak-scattering model incorporating three possible solar wind streams and dual observing frequencies is discussed and some results presented. A recent study found that the current sampling bandwidth limits the sensitivity of IPS observations at EISCAT. Methods of increasing the sensitivity, and the results of trials, are discussed
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